Exit polls show Modi’s Bharatiya Janata Party (BJP) winning most seats in at least three of the five contests while the beleaguered opposition Congress faces more humiliation, two years before general elections.
The results could also strengthen Modi’s hand in parliament’s upper house where his lack of a majority has stalled his reform agenda.
The main focus will be on Uttar Pradesh (UP) — home to 220 million people and the biggest electoral prize in the world’s largest democracy.
But the contest in Punjab will also be closely watched to see if the fledgling Aam Aadmi Party can secure a breakthrough and results are also due in the smaller states of Goa, Uttarakhand and northeastern Manipur.
Even the major cash shortages which followed November’s shock ban on high denomination bank notes appears to have done little damage to his standing, particularly with Congress in disarray.
“If the BJP wins in UP, it will not only bolster its position but quell all the fears about the BJP and Modi’s image being eroded by demonetisation,” said veteran political commentator Bharat Bhushan.
“A victory in UP will make Modi more confident… and he will be able to do what he wants to do.”
But the two biggest setbacks of his premiership came when the BJP was roundly beaten in elections for Delhi’s local assembly and the state of Bihar in 2015 so Modi won’t be taking anything for granted.
The multi-phase elections, which began in February, ended on Wednesday after which exit polls — that have proved unreliable in the past — were allowed to be published.
Nearly all predict the BJP will come out on top in Uttar Pradesh, Uttarakhand and Goa.
The AAP — an anti-corruption party led by Delhi’s Chief Minister Arvind Kejriwal — is tipped in some surveys to win Punjab.
– Congress crisis –
The only crumb of comfort for Congress — which has led India for most of the post-independence period — was in Manipur where forecasts give it the edge.
Yadav has been trying to tap into the pain from Modi’s cash ban, campaigning alongside Congress’ frontman Rahul Gandhi.
The BJP fared poorly in the last UP elections, winning only 47 out of 403 assembly seats, but it clinched 73 out of 80 parliamentary constituencies in 2014 with Modi standing in the holy city of Varanasi.
Even if the BJP fail to win, it will undoubtedly improve on its previous showing which could have significant implications for the make-up of the Rajya Sabha — the upper house of parliament.
Several of Modi’s key reforms such as a nationwide sales tax have stalled in the chamber due to his lack of a BJP majority.
Its make-up is based on parties’ strength in the state assemblies, with the biggest states supplying the largest number of MPs.
Nistula Hebbar, political editor of The Hindu newspaper, said Modi could find himself with the kind of power not seen for decades.
“These polls will tell us whether we are going back to the 1960s and 1970s, when there was only one strong national party. Back then it was the Congress, now it’s the BJP. The rest are all regional,” Hebbar said.
Congress did have high hopes of winning Punjab where the ruling party which is allied to the BJP has been tarnished by corruption scandals but Aam Aadmi now looks likely to be the beneficiary.
“If Congress loses Punjab it’ll have to think long and hard about its future,” Hebbar said.